Amherst College - Mikko Möttönenhttps://www.amherst.edu/taxonomy/term/20978
enPhysics Professor David Hall and Team Observe Quantum-Mechanical Monopoleshttps://www.amherst.edu/aboutamherst/news/news_releases/2015/04-2015/node/606239
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="fine-print">April 30, 2015</p>
<p class="fine-print" style="text-align:center;"><img alt="EN_Science_magneettinen_monpoli_21042015-1_400x400.jpg" class="media-image" height="407" title="EN_Science_magneettinen_monpoli_21042015-1_400x400.jpg" width="400" src="https://www.amherst.edu/system/files/media/EN_Science_magneettinen_monpoli_21042015-1_400x400.jpg" /></p>
<p class="fine-print" style="text-align:center;">An artistic illustration of a quantum-mechanical monopole. Credit: Heikka Valja.</p>
<p>AMHERST, Mass.—Building on <a href="https://www.amherst.edu/aboutamherst/news/faculty/node/532493">his own previous research</a>, Amherst College professor David S. Hall ’91 and a team of international collaborators have experimentally identified a pointlike monopole in a quantum field for the first time. The discovery, announced this week, gives scientists further insight into the elusive monopole magnet, an elementary particle that researchers believe exists but have not yet seen in nature.<!--break--></p>
<p>The development—explored in <a href="http://doi.org/10.1126/science.1258289">a paper published in <em>Science</em></a>—is a remarkable step forward in quantum research. A better understanding of the structure of monopoles and other topological entities is very valuable to scientists, in part because they appear in the models describing the first moments of the universe’s existence and affect the properties of many different materials, such as metals.</p>
<p>“This was a very exciting experiment to perform,” says former Amherst postdoctoral research associate Michael Ray, now a visiting assistant professor at Union College and the lead author of the paper. “These kinds of defects are relevant to theories that describe the early universe, so observing this monopole gives us a glimpse into those moments but on a much more accessible scale.”</p>
<p><img alt="image004_400x267.jpg" class="media-image" height="268" style="display: block; margin-left: auto; margin-right: auto;" title="image004_400x267.jpg" width="400" style="display: block; margin-left: auto; margin-right: auto;" src="https://www.amherst.edu/system/files/media/image004_400x267.jpg" /></p>
<p class="fine-print" style="text-align:center;">Hall and Ray in Hall’s Merrill Science Center lab</p>
<p>Hall and Ray manipulated a gas of rubidium atoms prepared in a nonmagnetic state near absolute zero temperature in an atomic refrigerator in Hall’s lab in Amherst’s Merrill Science Center. Under these extreme conditions, they were able to create monopoles in the quantum field of the ultracold gas.</p>
<p>“In this nonmagnetic state, a structure was created in the field describing the gas resembling the magnetic monopole particle as described in grand unified theories of particle physics,” said Aalto University (Finland) Academy Research Fellow Mikko Möttönen, a collaborator on the team who led the theoretical analysis of the monopole. “Previously, we have used the gas to detect a monopole within a so-called synthetic magnetic field, but there has been no monopole in the quantum field describing the gas itself. Now we have finally witnessed the quantum-mechanical monopole.”</p>
<p>Ordinarily, magnetic poles come in pairs: each magnet has both a north pole and a south pole. As the name suggests, however, a magnetic monopole is a magnetic particle possessing only a single, isolated pole—a north pole without a south pole, or vice versa. Despite extensive experimental searches, in everything from lunar samples (moon rock) to ancient fossilized minerals, no observation of a naturally occurring magnetic monopole has yet been confirmed.</p>
<p>In this case, the gas is in a nonmagnetic state, and no quantum whirlpools or monopoles are created in the synthetic magnetic field, Möttönen continued. However, quantum-mechanical magnetic order prevailed in the sample itself, and the team was able to manipulate it with adjustments to an externally applied magnetic field to generate the quantum-mechanical monopoles.</p>
<p>“In the experiment, the control of those magnetic fields must be stable to a small fraction of the size of the Earth’s magnetic field,” said Hall. “The main experimental challenge we faced was to prepare the ultracold gas under highly sensitive conditions, in which field fluctuations due to the motion of metal objects or power-line variations can make observation of the monopoles difficult.”</p>
<p>The team’s result is further evidence that quantum-mechanical monopole structures do exist in nature, he said, even if magnetic monopoles themselves remain at large.</p>
<p>A 1991 Amherst graduate, Hall is an experimental physicist specializing in Bose-Einstein condensation. He received A.M. and Ph.D. degrees from Harvard University and did postgraduate work at the University of Colorado.</p>
<p><em>This material is based upon work supported by the National Science Foundation under Grant No. PHY-1205822, the Academy of Finland (grant nos. 251748, 135794, and 272806), the Finnish Doctoral Programme in Computational Sciences and the Magnus Ehrnrooth Foundation. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or the other funders.</em></p>
<p><strong><span style="text-decoration:underline;">The article</span></strong></p>
<p>M.W. Ray, E. Ruokokoski, K. Tiurev, M. Möttönen and D.S. Hall</p>
<p>“Observation of isolated monopoles in a quantum field”</p>
<p><em>Science</em>, DOI: 10.1126/science.1258289 (2015)</p>
<p>Link: <a href="http://doi.org/10.1126/science.1258289">http://doi.org/10.1126/science.1258289</a></p>
<p>See also the previous work of the team on a monopole in a synthetic classical-like field:</p>
<p>“<a href="http://www.nature.com/nature/journal/v505/n7485/full/nature12954.html" target="_blank" title="Observation of Dirac monopoles in a synthetic magnetic field">Observation of Dirac Monopoles in a Synthetic Magnetic Field</a>”, <em>Nature</em> 505, 657 (2014).</p>
<p><strong><span style="text-decoration:underline;">Video and images</span></strong></p>
<p>A video and full-resolution images can be accessed at <a href="http://docs.unigrafia.fi/mottonen/">http://docs.unigrafia.fi/mottonen/</a> (username: <em>Preview</em>; password: <em>1x5D6u5</em>) starting on April 26 at 8 p.m. U.S. Eastern Daylight Time.</p>
<p><strong><span style="text-decoration:underline;">Special Notes to Reporters</span></strong></p>
<p>More information, including a copy of the paper and visuals, can also be found in the <em>Science</em> press package at <a href="http://www.eurekalert.org/jrnls/sci" target="_blank">http://www.eurekalert.org/jrnls/sci</a>. You will need your user ID and password to access this information.</p>
<p><strong><span style="text-decoration:underline;">About Amherst College</span></strong></p>
<p>Founded in 1821, Amherst is a highly selective, coeducational liberal arts college with 1,800 students from most of the 50 states and more than 30 other countries. Considered one of the nation’s best educational institutions, Amherst awards the B.A. degree in 38 fields of study. Sixty percent of Amherst students receive need-based financial aid.</p>
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<p> </p></div></div></div><div class="field field-name-taxonomy-vocabulary-1 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Tags:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/20979">magnetic monopole</a></div><div class="field-item odd"><a href="/taxonomy/term/11166">David S. Hall &#039;91</a></div><div class="field-item even"><a href="/taxonomy/term/20977">Michael Ray</a></div><div class="field-item odd"><a href="/taxonomy/term/20978">Mikko Möttönen</a></div><div class="field-item even"><a href="/taxonomy/term/22562">quantum physics</a></div></div></div><ul class="links inline"><li class="sharethis first last"><a href="/sharethis-ajax/606239" class="mm-sharethis">Share</a></li>
</ul>Wed, 29 Apr 2015 15:44:10 +0000channa606239 at https://www.amherst.eduhttps://www.amherst.edu/aboutamherst/news/news_releases/2015/04-2015/node/606239#commentsPhysics Professor David Hall and Team Observe Quantum-Mechanical Monopoleshttps://www.amherst.edu/aboutamherst/news/news_releases/2015/04-2015/node/606238
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="fine-print">April 30, 2015</p>
<p class="fine-print" style="text-align:center;"><img alt="EN_Science_magneettinen_monpoli_21042015-1_400x400.jpg" class="media-image" title="EN_Science_magneettinen_monpoli_21042015-1_400x400.jpg" height="407" width="400" src="https://www.amherst.edu/system/files/media/EN_Science_magneettinen_monpoli_21042015-1_400x400.jpg" /></p>
<p class="fine-print" style="text-align:center;">An artistic illustration of a quantum-mechanical monopole. Credit: Heikka Valja.</p>
<p>AMHERST, Mass.—Building on <a href="https://www.amherst.edu/aboutamherst/news/faculty/node/532493">his own previous research</a>, Amherst College professor David S. Hall ’91 and a team of international collaborators have experimentally identified a pointlike monopole in a quantum field for the first time. The discovery, announced this week, gives scientists further insight into the elusive monopole magnet, an elementary particle that researchers believe exists but have not yet seen in nature.</p>
<p>The development—explored in <a href="http://doi.org/10.1126/science.1258289">a paper published in <em>Science</em></a>—is a remarkable step forward in quantum research. A better understanding of the structure of monopoles and other topological entities is very valuable to scientists, in part because they appear in the models describing the first moments of the universe’s existence and affect the properties of many different materials, such as metals.</p>
<p>“This was a very exciting experiment to perform,” says former Amherst postdoctoral research associate Michael Ray, now a visiting assistant professor at Union College and the lead author of the paper. “These kinds of defects are relevant to theories that describe the early universe, so observing this monopole gives us a glimpse into those moments but on a much more accessible scale.”</p>
<p><img alt="image004_400x267.jpg" class="media-image" title="image004_400x267.jpg" height="268" style="display: block; margin-left: auto; margin-right: auto;" width="400" style="display: block; margin-left: auto; margin-right: auto;" src="https://www.amherst.edu/system/files/media/image004_400x267.jpg" /></p>
<p class="fine-print" style="text-align:center;">Hall and Ray in Hall’s Merrill Science Center lab</p>
<p>Hall and Ray manipulated a gas of rubidium atoms prepared in a nonmagnetic state near absolute zero temperature in an atomic refrigerator in Hall’s lab in Amherst’s Merrill Science Center. Under these extreme conditions, they were able to create monopoles in the quantum field of the ultracold gas.</p>
<p>“In this nonmagnetic state, a structure was created in the field describing the gas resembling the magnetic monopole particle as described in grand unified theories of particle physics,” said Aalto University (Finland) Academy Research Fellow Mikko Möttönen, a collaborator on the team who led the theoretical analysis of the monopole. “Previously, we have used the gas to detect a monopole within a so-called synthetic magnetic field, but there has been no monopole in the quantum field describing the gas itself. Now we have finally witnessed the quantum-mechanical monopole.”</p>
<p>Ordinarily, magnetic poles come in pairs: each magnet has both a north pole and a south pole. As the name suggests, however, a magnetic monopole is a magnetic particle possessing only a single, isolated pole—a north pole without a south pole, or vice versa. Despite extensive experimental searches, in everything from lunar samples (moon rock) to ancient fossilized minerals, no observation of a naturally occurring magnetic monopole has yet been confirmed.</p>
<p>In this case, the gas is in a nonmagnetic state, and no quantum whirlpools or monopoles are created in the synthetic magnetic field, Möttönen continued. However, quantum-mechanical magnetic order prevailed in the sample itself, and the team was able to manipulate it with adjustments to an externally applied magnetic field to generate the quantum-mechanical monopoles.</p>
<p>“In the experiment, the control of those magnetic fields must be stable to a small fraction of the size of the Earth’s magnetic field,” said Hall. “The main experimental challenge we faced was to prepare the ultracold gas under highly sensitive conditions, in which field fluctuations due to the motion of metal objects or power-line variations can make observation of the monopoles difficult.”</p>
<p>The team’s result is further evidence that quantum-mechanical monopole structures do exist in nature, he said, even if magnetic monopoles themselves remain at large.</p>
<p>A 1991 Amherst graduate, Hall is an experimental physicist specializing in Bose-Einstein condensation. He received A.M. and Ph.D. degrees from Harvard University and did postgraduate work at the University of Colorado.</p>
<p><em>This material is based upon work supported by the National Science Foundation under Grant No. PHY-1205822, the Academy of Finland (grant nos. 251748, 135794, and 272806), the Finnish Doctoral Programme in Computational Sciences and the Magnus Ehrnrooth Foundation. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or the other funders.</em></p>
<p><strong><span style="text-decoration:underline;">The article</span></strong></p>
<p>M.W. Ray, E. Ruokokoski, K. Tiurev, M. Möttönen and D.S. Hall</p>
<p>“Observation of isolated monopoles in a quantum field”</p>
<p><em>Science</em>, DOI: 10.1126/science.1258289 (2015)</p>
<p>Link: <a href="http://doi.org/10.1126/science.1258289">http://doi.org/10.1126/science.1258289</a></p>
<p>See also the previous work of the team on a monopole in a synthetic classical-like field:</p>
<p>“<a href="http://www.nature.com/nature/journal/v505/n7485/full/nature12954.html" target="_blank" title="Observation of Dirac monopoles in a synthetic magnetic field">Observation of Dirac Monopoles in a Synthetic Magnetic Field</a>”, <em>Nature</em> 505, 657 (2014).</p>
<p><strong><span style="text-decoration:underline;">Video and images</span></strong></p>
<p>A video and full-resolution images can be accessed at <a href="http://docs.unigrafia.fi/mottonen/">http://docs.unigrafia.fi/mottonen/</a> (username: <em>Preview</em>; password: <em>1x5D6u5</em>) starting on April 26 at 8 p.m. U.S. Eastern Daylight Time.</p>
<p><strong><span style="text-decoration:underline;">Special Notes to Reporters</span></strong></p>
<p>More information, including a copy of the paper and visuals, can also be found in the <em>Science</em> press package at <a href="http://www.eurekalert.org/jrnls/sci" target="_blank">http://www.eurekalert.org/jrnls/sci</a>. You will need your user ID and password to access this information.</p>
<p><strong><span style="text-decoration:underline;">About Amherst College</span></strong></p>
<p>Founded in 1821, Amherst is a highly selective, coeducational liberal arts college with 1,800 students from most of the 50 states and more than 30 other countries. Considered one of the nation’s best educational institutions, Amherst awards the B.A. degree in 38 fields of study. Sixty percent of Amherst students receive need-based financial aid.</p>
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<p> </p>
<p> </p></div></div></div><div class="field field-name-taxonomy-vocabulary-1 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Tags:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/20979">magnetic monopole</a></div><div class="field-item odd"><a href="/taxonomy/term/11166">David S. Hall &#039;91</a></div><div class="field-item even"><a href="/taxonomy/term/20977">Michael Ray</a></div><div class="field-item odd"><a href="/taxonomy/term/20978">Mikko Möttönen</a></div><div class="field-item even"><a href="/taxonomy/term/22562">quantum physics</a></div></div></div><ul class="links inline"><li class="sharethis first last"><a href="/sharethis-ajax/606238" class="mm-sharethis">Share</a></li>
</ul>Wed, 29 Apr 2015 15:43:57 +0000channa606238 at https://www.amherst.eduAmherst College Physicists Create Synthetic Magnetic Particlehttps://www.amherst.edu/aboutamherst/news/faculty/node/532493
<div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p class="fine-print">January 29, 2014</p>
<p><img alt="" class="media-image" height="336" title="" width="600" src="https://www.amherst.edu/system/files/media/DavidHallMichaelRay_600px.jpg" /></p>
<p class="fine-print">Physics Professor David Hall and Postdoctoral Associate Michael Ray. <br>Editor's note: High-resolution photos are available upon request.</p>
<p>AMHERST, Mass.—Nearly 85 years after pioneering theoretical physicist Paul Dirac predicted the possibility of their existence, an international collaboration led by Amherst College Physics Professor David S. Hall ’91 and Aalto University (Finland) Academy Research Fellow Mikko Möttönen has created, identified and photographed synthetic magnetic monopoles in Hall’s laboratory on the Amherst campus. <!--break-->The groundbreaking accomplishment paves the way for the detection of the particles in nature, which would be a revolutionary development comparable to the discovery of the electron.</p>
<p><a href="http://dx.doi.org/10.1038/nature12954">A paper</a> about this work co-authored by Hall, Möttönen, Amherst postdoctoral research associate Michael Ray, Saugat Kandel ’12 and Finnish graduate student Emmi Ruokokski was published today in the journal <em>Nature</em>.</p>
<p style="text-align:center;"><div id="video-filter-55be0be39a9c2" style="width: 100%; max-width: 453px;"><iframe src="https://www.youtube.com/embed/HSDoIf5FY2s?rel=1&amp;autoplay=0&amp;wmode=opaque" width="100%" height="100%" class="video-filter video-youtube vf-hsdoif5fy2s" frameborder="0" scrolling="auto"></iframe></div><script>(function ($) {
setTimeout(function(){
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$('#video-filter-55be0be39a9c2').height(height);
}, 1000);
$(window).resize(function() {
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<p class="fine-print" style="text-align:center;">Watch the video, "Making Monopoles."</p>
<p>“The creation of a synthetic magnetic monopole should provide us with unprecedented insight into aspects of the natural magnetic monopole—if indeed it exists,” said Hall, explaining the implications of his work.</p>
<p>Ray, the paper’s lead author and first to sight the monopoles in the laboratory, agreed, noting: “This is an incredible discovery. To be able to confirm the work of one of the most famous physicists is probably a once-in-a-lifetime opportunity. I am proud and honored to have been part of this great collaborative effort.”</p>
<p>Ordinarily, magnetic poles come in pairs: they have both a north pole and a south pole. As the name suggests, however, a magnetic monopole is a magnetic particle possessing only a single, isolated pole—a north pole without a south pole, or vice versa. In 1931, Dirac published a paper that explored the nature of these monopoles in the context of quantum mechanics. Despite extensive experimental searches since then, in everything from lunar samples—moon rock—to ancient fossilized minerals, no observation of a naturally-occurring magnetic monopole has yet been confirmed.</p>
<p>Hall’s team adopted an innovative approach to investigating Dirac’s theory, creating and identifying synthetic magnetic monopoles in an artificial magnetic field generated by a Bose-Einstein condensate, an extremely cold atomic gas tens of billionths of a degree warmer than absolute zero. The team relied upon theoretical work published by Möttönen and his student Ville Pietilä that suggested a particular sequence of changing external magnetic fields could lead to the creation of the synthetic monopole. Their experiments subsequently took place in the atomic refrigerator built by Hall and his students in his basement laboratory in the Merrill Science Center.</p>
<p>After resolving many technical challenges, the team was rewarded with photographs that confirmed the monopoles’ presence at the ends of tiny <a href="https://www.amherst.edu/aboutamherst/news/faculty/node/224501">quantum whirlpools</a> within the ultracold gas. The result proves experimentally that Dirac’s envisioned structures do exist in nature, explained Hall, even if the naturally occurring magnetic monopoles remain at large.</p>
<p><img alt="" class="media-image" height="392" style="display: block; margin-left: auto; margin-right: auto;" title="" width="400" style="display: block; margin-left: auto; margin-right: auto;" src="https://www.amherst.edu/system/files/media/hall_figure1_400x392.jpg" /></p>
<p class="fine-print" style="text-align:center;">Artistic illustration of the synthetic magnetic monopole, courtesy of <a href="http://www.heikkavalja.com/">Heikka Valja</a>. <br><a href="http://materialbank.aalto.fi/public/a8e60d8ec882.aspx">Click for the full-resolution image</a>.</p>
<p>Finally seeing the synthetic monopole, said Hall, was one of the most exciting moments in his career. “It’s not every day that you get to poke and prod the analog of an elusive fundamental particle under highly controlled conditions in the lab.” He added that creation of synthetic electric and magnetic fields is a new and rapidly expanding branch of physics that may lead to the development and understanding of entirely new materials, such as higher-temperature superconductors for the lossless transmission of electricity. He also said that the team’s discovery of the synthetic monopole provides a stronger foundation for current searches for magnetic monopoles that have even involved the famous Large Hadron Collider at CERN, the European Organization for Nuclear Research. (Older theoretical models that described the post-Big Bang period predicted that they should be quite common, but a special model for the expansion of the universe that was later developed explained the extreme rarity of these particles.)</p>
<p>Added Aalto’s Möttönen: “Our achievement opens up amazing avenues for quantum research. In the future, we want to get even a more complete correspondence with the natural magnetic monopole.”</p>
<p>Hall, who was recently named a Fellow of the American Physical Society, said his team’s experimental work arose out of interest from Amherst summer student researchers at a group meeting in 2011, well after Pietilä and Möttönen’s 2009 paper had appeared in <em>Physical Review Letters</em>. “It felt as though Pietilä and Möttönen had written their letter with our apparatus in mind,” he said, “so it was natural to write them with our questions. Were it not for the initial curiosity on the part of the students we would never have embarked on this project.”</p>
<p><em>This material is based upon work supported by the National Science Foundation under grants nos. PHY-0855475 and PHY-1205822, by the Academy of Finland through its Centres of Excellence Program (grant no. 251748) and grants nos. 135794, 272806 and 141015, and the Finnish Doctoral Programme in Computational Sciences. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or the other funders.</em></p></div></div></div><div class="field field-name-taxonomy-vocabulary-1 field-type-taxonomy-term-reference field-label-above"><div class="field-label">Tags:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/term/4376">david s. hall</a></div><div class="field-item odd"><a href="/taxonomy/term/20977">Michael Ray</a></div><div class="field-item even"><a href="/taxonomy/term/20978">Mikko Möttönen</a></div><div class="field-item odd"><a href="/taxonomy/term/20979">magnetic monopole</a></div><div class="field-item even"><a href="/taxonomy/term/20980">Dirac monopole</a></div><div class="field-item odd"><a href="/taxonomy/term/20981">the journal Nature</a></div><div class="field-item even"><a href="/taxonomy/term/20982">magnetic particle</a></div><div class="field-item odd"><a href="/taxonomy/term/20983">CERN</a></div><div class="field-item even"><a href="/taxonomy/term/1978">Merrill Science Center</a></div><div class="field-item odd"><a href="/taxonomy/term/20984">quantum whirlpools</a></div><div class="field-item even"><a href="/taxonomy/term/20985">Paul Dirac</a></div></div></div>Wed, 22 Jan 2014 17:31:00 +0000channa532493 at https://www.amherst.eduhttps://www.amherst.edu/aboutamherst/news/faculty/node/532493#comments